Lennox International Inc. G61MP manual

Page 1 © 2003 Lennox Industries Inc. Corp. 0308−L6 G61MP Service Literature Revised 10−2004 G61MP SERIES UNITS G61MP series units are high−ef ficiency multi−position (up- flow , downflow , horizontal right and lef t) gas furnaces manufactured with Lennox Duralok Plus t heat exchang- ers formed of aluminized steel. G61MP units are available[...]

Page 2 SPECIFICA TIONS Gas Ht i ModelNo. G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090 Heating Performance High Fi Input− Btuh (kW) 44,000 (12.9) 66,000 (19.3) 88,000 (25.8) 88,000 (25.8) Performance g Fire Output− Btuh (kW) 41,000 (12.0) 62,000 (18.2) 83,000 (24.3) 84,000 (24.6) T emperature ris e range − _[...]

Page 3 SPECIFICA TIONS Gas Ht i ModelNo. G61MP−48C−1 10 G61MP−60C−1 10 G61MP−60D−135 Heating Performance High Fi re Input− Btuh (kW) 1 10,000 (32.2) 1 10,000 (32.2) 132,000 (38.7) P er f ormance g Output− Btuh (kW) 104,000 (30.5) 104,000 (30.5) 124,000 (36.3) T emperature rise range − _ F ( _ C) 45 − 75 (25 − 42) 35 ?[...]

Page 4 BLOWER DA T A G61MP−36B−045 PERFORMANCE (Less Filter) External St atic Air V olume / Watt s at Different Blower Speeds External St atic Pressure High Medium−High Medium−Low Low in. w.g. Pa cfm L/s W att s cfm L/s W att s cfm L/s Watt s cfm L/s W att s 0.00 25 1555 735 630 1410 665 585 1 190 560 520 1030 485 435 0.10 25 1515 715 605 1[...]

Page 5 BLOWER DA T A G61MP−60C−090 PERFORMANCE (Less Filter) − Single Side Return Air − Air volumes in bold require field fabricated transi- tion to accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) air filter in order to maintain proper air velocity . External St atic Air V olume / Watt s at Different Blower Speeds External St atic Pressure [...]

Page 6 BLOWER DA T A G61MP−60C−1 10 PERFORMANCE (Less Filter) − Bottom Return Air , Side Return Air with Optional RAB Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side. External St atic P Air V olume / Watt s at Different Blower Speeds Pressure High Medium−High Medium−Low Low in. w.g. Pa cfm L/s W att s cf[...]

Page 7 G61MP P ARTS ARRANGEMENT FIGURE 1 TOP CAP CABINET BURNER BOX ASSEMBLY SIGHT GLASS DuralokPlus TM HEA T EXCHANGER ASSEMBLY CONDENSER COIL CONTROL BOX DOOR INTERLOCK SWITCH COLD HEADER (COLLECTOR) BOX COMBUSTION AIR INDUCER BLOWER ACCESS DOOR BURNER ACCESS P ANEL FLUE COLLAR COMBUSTI ON A I R P R O V E PR OV E SWITCHES* PRIMARY LIMIT WARM HEAD[...]

Page 8 I−UNIT COMPONENTS G61MP unit components are shown in figure 1. The gas valve, combustion air inducer and burners can be ac- cessed by removing the burner access panel. Electrical component s are in the control box (figure 2) found in the blower section. G61MP units are factory equipped with a bottom return air panel in place. The panel is [...]

Page 9 onds. A f ter a total of five trials for ignition (including the ini- tial trial), the control goes into W atchguard−Flame Failure mode. A f ter a 60−minute reset period, the control will begin the ignition sequence again. Th e SureLight control board has an added feature that pro- longs the life of the ignitor . After a successful ignit[...]

Page 10 TWO−ST AGE INTEGRA TED CONTROL BOARD FIGURE 4 THERMOST A T CONNECTIONS (TB1) DIP SWITCHES 1 − 4 LEDs W915 F ACTOR Y INST ALLED JUMPER (MUST CLIP FOR 2 ST AGE COOL) DIP SWITCH(ES) FUNCTION 1 and 2 Blower Off Delay (Heating Mode) 3 Second Stage ON Delay (Single−st age t’st at) 4 Blower Off Delay (Cooling Mode) T ABLE 3 Integrated Cont[...]

Page 1 1 T ABLE 6 DIAGNOSTIC CODES Diagnostic LEDs are labeled DS1 and DS2. See figure 4 for location of diagnostic LEDs. DS1 DS2 DESCRIPTION SIMUL T ANEOUS SLOW FLASH SIMUL T ANEOUS SLOW FLASH Power on − Normal operation. Also signaled during cooling and continuous fan. SIMUL T ANEOUS F AST FLASH SIMUL T ANEOUS F AST FLASH Normal operation − s[...]

Page 12 C−Heating Component s 3. Flame Sensor A flame sensor is located on the left side of the burner sup- port. See figure 6. The sensor is mounted through the bot- tom of the burner box and the tip protrudes into the flame envelope of the left−most burner . The sensor can be re- moved for service without removing any p art of the burn- ers. [...]

Page 13 6. Clamshell Heat Exchanger G61MP units use a n aluminized steel primar y and s tain - less steel secondary heat exchanger assembly . Heat is transferr ed t o the air stream from all surfaces of the heat exchanger . The shape of the heat exchanger ensures maximum ef ficiency . The combustion air inducer pulls fresh air through the air intak[...]

Page 14 On heat demand (first or second stage) the switch senses that the combustion air inducer is operating. It closes a cir- cuit to the furnace control when pressure inside the cold end header box decreases to a certain set point. Se t points vary depending on unit size. See tables 8, 9 and 10 . The pressure sensed by the switch is negative. If[...]

Page 15 12. Combustion Air Inducer (B6) All G 61MP u nits use a combustion air inducer t o m ove a ir through the burners and heat exchanger during heating operation. The blower uses a PSC 120V AC motor . Th e motor operates during all heating operation and is con- trolled by the ignition control A3. Blower operates continu- ously while there is a [...]

Page 16 II−PLACEMENT AND INST ALLA TION T ABLE 1 1 OUTDOOR TERMINA TION KITS AND CORRESPONDING EQUIV ALENCIES V ent Pipe Length Equivalency (feet) UNIT MODEL VENT PIPE DIA. (in.) Outdoor Exhaust Accelerator (Dia. X Length) Outdoor Exhaust Accelerator (Dia. X Length) 1−1/2" Concen- tric Kit 2" Con- centric Kit 3" Con- centric Kit [...]

Page 17 A−V ent Piping Guidelines The G61MP can be inst alled as either a N on−Direct V ent or a Direct V ent gas central furnace. NOTE − In Non-Direc t V ent installations, combustion air is taken f rom i ndoors and f lue g ases are d ischarged outdoors. In D irect V ent installations, c ombustion a ir i s t ak en f rom o ut- doors and flue [...]

Page 18 Us e the following steps to correctly size vent pipe diameter . 1 − Determine the vent termination and its corresponding equivalent feet value according to table 1 1. 2 − Determine the number of 90° elbows required for both indoor and out door (e.g. snow riser) use. Calculate th e corresponding equivalent feet of vent pipe. 3 − Deter[...]

Page 19 C− V enting Practices The thickness of construction through which vent pipes may be installed is 24" (610mm) maximum and 3" (76mm) minimum. If a G61MP furnace replaces a furnace which wa s commonly vented with another gas appliance, the size of the existing vent pipe for that gas appliance must be checked. Without the heat of th[...]

Page 20 FIGURE 14 TYPICAL EXHAUST PIPE CONNECTIONS HORIZONT AL DIRECT OR NON-DIRECT VENT APPLICA TIONS (Horizontal Right-Hand Air Discharge Application Shown) G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090 G61MP−48C−1 10* G61MP−60C−1 10* G61MP−60C−135* G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP?[...]

Page 21 TYPICAL AIR INT AKE PIPE CONNECTIONS UPFLOW OR DOWNFLOW DIRECT VENT APPLICA TIONS (Right-Hand Exit in Upflow Application Shown) FIGURE 15 PLUG (Must be glued in place) G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090 G61MP−48C−1 10* G61MP−60C−1 10* G61MP−60C−135* G61MP−36B−045 G61MP−36B−070 G61MP?[...]

Page 22 TYPICAL AIR INT AKE PIPE CONNECTIONS DOWNFLOW NON-DIRECT VENT APPLICA TIONS (Right-Hand Exit in Downflow Applications Shown) FIGURE 18 PLUG (Must be glued in place) 6 in. Max. PLUG (Must be glued in place) Downflow Additive Flloor Base 18 in. Downflow Evaporator Coil 2" 2" SWEEP ELL 2" SWEEP ELL INT AKE DEBRIS SCREEN (Provide[...]

Page 23 3 − T o the extent that it is pr actical, clos e all building doors and windows and all doors between the space in which the appliances connected to the venting sys tem are lo- cated and other spaces of the building. 4 − C lose fir eplace damper s. 5 − Turn on clothes dryers and any appliances not con- nected to the venting system. T [...]

Page 24 FIGURE 19 VENT TERMINA TION CLEARANCES FOR INST ALLA TIONS IN THE USA AND CANADA* A − Clearance above grade − 12 in. (305mm) minimum. B − Clearance to window or door that may be opened − for vent inst allations in USA − 12 in. (305mm) minimum. for vent installat ions in Canada − 12 in. (305mm) minimum for appliances  100,000 [...]

Page 25 Details o f Intake and Exhaust Pi ping T erminations f o r Direct V ent Installations NOTE − In Direct Vent installations, combustion air is taken from outdoors and flue gases are disc harged to outdoors. Intake and ex haust pipes may be routed either horiz ontally through a n o utside w all o r v ertically t hr ough the roof. In at- tic [...]

Page 26 FIGURE 22 12" (305) ABOVE A VERAGE SNOW ACCUMULA TION EXHAUST EXHAUST TERMINA TION INT AKE TERMINA TION INT AKE Inches (mm) DIRECT VENT CONCENTRIC ROOFTOP TERMINA TION (71M80, 69M29 or 60L46) FIELD−PROVIDED REDUCER MA Y BE REQUIRED TO ADAPT LARGER VENT PIPE SIZE TO TERMINA TION FIGURE 23 EXHAUST EXHAUST TERMINA TION INT AKE TERMINA T[...]

Page 27 FIGURE 27 12" MIN. (305) Above Grade COVER EXHAUST VENT WITH 1/2" (13) FOAM INSULA TION Front View Side View DIRECT VENT TERMINA TION W ALL TERMINA TION KIT (22G44, 44J40, 30G28 or 81J20) EXTENDED VENT FOR GRADE CLEARANCE Inches (mm) 5" (127) 5-1/2" (140) EXHAUST AIR INT AKE AIR GRADE 12" (305) 8" (203) Minimum[...]

Page 28 3. I f exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, pip- ing must be supported every 3 feet (.9m) as shown in figure 12. Refer to figure 31 for proper piping method. When exhaust piping must be run up an out side wall, any reduction in exhaust pipe size must be done after the final elb[...]

Page 29 hose clamp. Condensate li ne must be sloped downward away from condensate trap to drain. If drain level is above con- densate trap, condensate pump must be used. Con- densate drain line should be routed within the condi- tioned sp ace to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat cable kit may b[...]

Page 30 III−ST ART-UP A−Preliminary and Seasonal Checks 1 − Inspect electric al wiring, both field and factory ins talled for loose connections . T ighten as required. 2 − Check volt age at disconnect switch. V oltage must be within range listed on the nameplate. If not, consult the power comp any and have volt age condition corrected befor[...]

Page 31 WHITE RODGERS 36E SERIES GAS V AL VE GAS V AL VE SHOWN IN OFF POSITION HIGH FIRE MANIFOLD PRESSURE ADJUSTMENT ON SIDE (under cap) MANIFOLD PRESSURE T AP ON SIDE INLET PRESSURE T AP ON SIDE LOW FIRE MANIFOLD PRESSURE ADJUSTMENT ON SIDE (under cap) FIGURE 36 8 − Honeywell VR8205 Gas V alve − T urn knob on gas valve counterclockwise to ON [...]

Page 32 When checking piping connections for gas leaks , us e pre - ferred means. Kitc hen detergents can cause har mful corro - sion on various metals used i n gas piping. Use of a specialty Gas Leak Detector is strongly rec ommended. It is available through Lennox under part number 31B2001. See Cor p. 841 1−L10, for further details. Do not use [...]

Page 33 T ABLE 17 High Heat Unit CO 2 % For Nat CO 2 % For L.P . G61MP−36B−045 6.5 − 7.5 7.4 − 8 .4 G61MP−36B−070 6 .5 − 7 .5 7.4 − 8 .4 G61MP−48C−090 6 .9 − 7 .9 7.8 − 8 .8 G61MP−60C−090 6 .9 − 7 .9 7.8 − 8 .8 G61MP−48C−1 10 7 .2 − 8 .2 8.1 − 9 .1 G61MP−60C−1 10 7 .2 − 8 .2 8.1 − 9 .1 G61MP−60D−1[...]

FIGURE 3 8 TRANSDUCER (P ART #78H5401) FIGURE 40 ST A TIC PRESSURE TEST Page 34 J−Flame Signal A microamp DC meter is needed to check the flame signal on the ignition control. Flame (microamp) signal is an electrical current which passes from the furnace control through the sensor during unit opera - tion. Current passes from the sensor through t[...]

Page 35 D−Blower Speed T aps Blower speed tap changes are made on the SureLight con- trol board. See figure 4. The unused tap must be secured on dummy terminals "P ARK " on the SureLight board. The high heating t ap is connected to the "HI HEA T " terminal an d the low heating / continuous blower tap is connected to t h e &quo[...]

Page 36 FIGURE 41 Remove and discard two shipping screws. G61MP−135 ONL Y 9 − Remove 3/8 inch rubber cap from condensate drain plug and drain. Replace cap af ter draining. 10 − Disconnect condensate drain line from the conden- sate trap. Remove condensate trap (it may be neces- sary to cut drain pipe). Remove screws that secure condensate col[...]

Page 37 Cleaning the Burner Assembly 1 − T urn off electrical and gas power supplies to furnace. Remove upper and lower furnace access panels. 2 − Mark all gas valve wires and disconnect them from the valve. 3 − Disconnect t he gas supply line from the gas valve. Re- move gas valve/manifold assembly . 4 − Mark and disconnect sensor wire fro[...]

Page 38 VII− Wiring and Sequence of Operation[...]

Page 39 Sequence of Operation Sequence depends on type thermost at used. G61MP units are applicable for single s tage or two stage ther- mostat s. Both type thermostat s are described below . Thermostat jumper E20 dictates which mode unit will operate in. See flow chart for more sequence det ail. SureLight Control Self Check When there is a call fo[...]

Page 40 HEA TING SEQUENCE OF OPERA TION NORMAL AND ABNORMAL HEA TING MODE CONTROL SELF−CHECK OKA Y? YES GAS V AL VE OFF . COMBUSTION AIR INDUCER OFF . INDOOR BLOWER OFF . (RESET CONTROL BY TURNING MAIN POWER OFF .) DS1 ON, DS2 ON NO POLARITY REVERSED. DS1 −− F AST FLASH DS2 −− SLOW FLASH POWER ON POLARITY OKA Y? NO SIGNAL HOLDS UNTIL UNIT[...]

Page 41 HEA TING SEQUENCE OF OPERA TION FIRST−ST AGE (LOW FIRE) PRESSURE SWITCH CLOSED WITHIN 2.5 MINUTES? GAS V AL VE OFF . COMBUSTION AIR INDUCER OFF . INDOOR BLOWER OFF . UNIT WILL RETRY AFTER 5−MINUTE WAIT PERIOD. DS1 OFF , DS2 SLOW FLASH. YES NO 15−SECOND COMBUSTION AIR INDUCER PRE−PURGE INITIA TED BY CLOSED FIRST−ST AGE PRESSURE SWI[...]

Page 42 HEA TING SEQUENCE OF OPERA TION LOW FLAME SIGNAL (Does not affect control operation) DS1 SLOW FLASH, DS2 F AST FLASH. FLAME SIGNAL ABOVE ( u 0.22 microamps) NO YES CONTINUED ON NEXT P AGE YES SINGLE−ST AGE THERMOST A T MODE (E20 SET A T SINGLE") TWO ST AGE THERMOST A T MODE (E20 SET A T TWO") YES YES ST ART SECOND−ST AGE[...]

Page 43 HEA TING SEQUENCE OF OPERA TION ARE PRIMARY , SECONDARY , ROLLOUT AND BACKUP SECONDARY LIMIT SWITCHES CLOSED? NO GAS V AL VE OFF . COMBUSTION AIR INDUCER OFF . INDOOR BLOWER ON. DS1 SLOW FLASH, DS2 ON. HAS PRIMARY , SECONDARY , ROLLOUT OR BACKUP SECONDARY LIMIT SWITCH CLOSED WITHIN 3 MINUTES? NO LIMIT SWITCH WA TCHGUARD MODE. GAS V AL VE OF[...]

Page 44 COOLING SEQUENCE OF OPERA TION SIGNAL POLARITY REVERSED. DS1 F AST FLASH, DS2 SLOW FLASH. POWER ON YES IS POLARITY REVERSED? THERMOST A T CALLS FOR FIRST−ST AGE COOL. COMPRESSOR AND CONDENSER F AN ENERGIZED. NO IS THERE PROPER GROUND? IS VOL T AGE ABOVE 75 VOL TS? LOW VOL T AGE SIGNAL A T DS HOLDS UNTIL VOL T AGE RISES ABOVE 75 VOL TS. NO[...]

Page 45 CONTINUOUS LOW SPEED F AN SEQUENCE OF OPERA TION MANUAL F AN SELECTION MADE A T THERMOST A T . AFTER 2 SECOND DELA Y , INDOOR BLOWER IS ENERGIZED ON CONTINUOUS F AN SPEED (LOW HEA T / LOW COOL). THERMOST A T CALLS FOR FIRST−ST AGE HEA T . THERMOST A T CALLS FOR FIRST ST AGE COOL. YES YES BURNERS IGNITE AND INDOOR BLOWER CONTINUES TO OPERA[...]

Page 46 VIII− Field Wiring Applications and Jumper Settings Field Wiring Applications Jumper Settings (See figure 4) Thermost at E20 W915 Y1 to Y2 Wiring Connections 1 Heat / 1 Cool NOTE − Us e dip switch 3 to set second−s tage heat ON delay . ON−10 minutes . OFF−15 minutes. SINGLE Leave Installed S1 T’STAT CONTROL TERM. STRIP OUTDOOR U[...]

Page 47 Field Wiring Applications (Continued) Jumper Settings (See figure 4) Thermost at E20 W915 Y1 to Y2 Wiring Connections FM21 Heat Pump / 1 Cool SINGLE Leave Installed CONTROL TERM. STRIP FM21 75VA, 24V TRANSFORMER* *Disconnect existing furnace transformer and re- place with 75VA, 24V trans- former if defrost option to be used. NOTE − Wiring[...]

Page 48 IX−SURELIGHT ® CONTROL TROUBLESHOOTING CHART UPON INITIAL POWER UP , REMOVE ALL THERMOST A T DEMANDS TO THE UNIT PROBLEM: 1 UNIT F AILS T O OPERA TE IN THE COOLING , HEA TING , OR CONTINUOUS F AN MODE Condition Possible Cause Corrective Action / Comment s 1.1 − Both diagnostic lights fail to light up. 1.1.1 Main voltage 120V not suppli[...]

Page 49 PROBLEM 1: UNIT F AILS TO OPERA TE IN THE COOLING , HEA TING , OR CONTINUOUS F AN MODE Condition Possible Cause Corrective Action / Comment s 1.5 − Diagnostic lights flash the improper main ground. 1.5.1 Improper ground to the unit. ACTION 1 − Check that the unit is properly ground. ACTION 2 − Install a proper main ground to the unit [...]

Page 50 PROBLEM 2: UNIT F AILS T O FIRE IN THE HEA TING MODE, COMBUSTION AIR INDUCER DOES NOT ENERGIZE (CONT .). Condition Possible Cause Corrective Action/Comments 2.3 − Unit operates with a cooling and con- tinuous fan demand. − Combustion air inducer will not start with a Heating demand. − Diagnostic lights flash the pressure switch failur[...]

Page 51 PROBLEM 4: UNIT F AILS TO FIRE IN THE HEA TING MODE, COMBUSTION AIR BLOWER ENERGIZES, IGNITOR IS ENERGIZED. Condition Possible Cause Corrective Action/Comments 4.1 − Unit operates with a cooling and continuous fan demand. Combustion air inducer energizes 4.1.1 Check that gas is being supplied to the unit. ACTION 1 − Check line pressure [...]

Page 52 PROBLEM 5: BURNERS LIGHT WITH HEA TING DEMAND BUT UNIT SHUTS DOWN PREMA TUREL Y (CONT .) Condition Possible Cause Corrective Action/Comments 5.3 − Combustion air inducer energizes with a heating demand. − Burners light. − Roll−out switch trips during the heating demand. − Diagnostic lights flash roll−out fail- ure. 5.3.1 Unit is[...]

Page 53 PROBLEM 6: CONTROL SIGNALS LOW FLAME SENSE DURING HEA TING MODE Condition Possible Cause Corrective Action/Comments 6.0 − Unit operates correctly but the diag- nostic lights flash low flame sense code 6.1.1 Sensor rod is improperly located on the burner . ACTION 1 − Check the sensor rod for proper loca- tion on the burner . Properly loc[...]

Page 54 SERVICE NOTES[...]